Microsampling device with re-use prevention

ABSTRACT

A lancing device including a spring-driven lancet translationally mounted within a housing. The lancet has at least one resilient finger extending outwardly therefrom and engageable within a cooperating recess formed in the housing to prevent re-use of the lancing device. A depth-adjustment knob is optionally included for contacting the housing to limit the travel of the lancet and thereby control the depth of penetration.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/353,917, filed Jan. 31, 2002, the entirety ofwhich is hereby incorporated herein by reference for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of lancing devicesfor sampling of blood or other body fluids, and more particularly to asingle-use lancing device that prevents re-use.

2. Description of Related Art

Samples of blood must sometimes be collected from a human or animalsubject. For example, many diabetics must periodically monitor theirblood glucose level by collecting a small blood sample from theirfingertip, forearm, or other body part, and chemically testing the bloodsample. Small blood samples are also commonly collected prior toaccepting a donor's blood at blood drives, to determine the donor=sblood type and to screen potential donors for anemia or otherconditions.

Lancing devices are commonly used to pierce the skin of a subject forsampling of blood, interstitial fluid, and/or other bodily fluids.Typically, a lancing device incorporates a spring-driven lancet and sometype of triggering mechanism to release energy stored in the spring todrive the sharp edge or point of the lancet to penetrate the subject'sskin. Various mechanisms also are known for limiting the travel of thelancet to control the depth of penetration of the lancet point into theskin, thereby minimizing trauma to the subject. However, many knowndepth-adjustment mechanisms are complex to manufacture and use, and/orhave multiple components engaged between the lancet tip and the depthcontrol element, thereby limiting the accuracy of depth control due totolerance “stacking”. The risks of disease transmission due to transferof blood and other bodily fluids are well known. One known manner ofdisease transmission is by reuse of needles or other sharp objects thathave been contaminated with the blood of another subject. Re-use of alancing device on different subjects, unintentionally or otherwise,could result in infection of the subsequent subjects through thistransmission mechanism.

Thus, it has been found that needs exist for an improved lancing devicethat prevents intentional or accidental re-use. Needs further exist fora simple and accurate depth control mechanism for a lancing device. Itis to these and other needs that the present invention is primarilydirected.

SUMMARY OF THE INVENTION

Briefly described, in its preferred embodiments, the present inventionrelates generally to an improved lancing device. In example embodiments,the lancing device of the present invention prevents reuse after asingle lancing action to prevent potential bloodborne diseasetransmission. In addition, example embodiments of the device of thepresent invention permit the user to adjust the penetration depth of thelancet.

In one embodiment, the present invention is a single-use lancing device.The device preferably includes a housing having a first end, a secondend, and a chamber between the first and second ends. The first end ofthe housing preferably defines a lancet opening, and the housingpreferably also includes at least one internal shoulder and a flangeextending across at least a portion of the chamber. A lancet ispreferably translationally mounted within the chamber of the housing formovement between a cocked position and a lancing position. The lancethas a lancet tip for passage through the lancet opening of the housingin the lancing position, and at least one finger for engaging theinternal shoulder of the housing after firing to prevent reuse. A springis preferably engaged between the lancet and the flange of the housingto drive the lancet from the cocked position toward the lancing positionupon firing of the lancing device. A cocking arm is preferably connectedto the lancet, and preferably includes at least one fin for releasableengagement with the flange of the housing to constrain the lancet in thecocked position.

In another embodiment, the present invention is a single-use lancingdevice including a spring-driven lancet that is translationally mountedwithin a housing. The lancet preferably includes at least one resilientfinger extending outwardly therefrom, each finger being engageablewithin a cooperating recess formed in the housing to prevent re-use ofthe lancing device.

Another embodiment of the present invention is a lancing deviceincluding a housing having a first end, a second end, and at least oneside wall defining a chamber between the first and second ends. A lancetis preferably translationally mounted within the chamber of the housing.A spring is preferably engaged between the lancet and the housing todrive the lancet from a cocked position toward a lancing position uponfiring of the lancing device. A cocking arm is preferably connected tothe lancet, the cocking arm preferably having at least one fin forreleasable engagement with the housing to constrain the lancet in thecocked position. The device preferably also includes a depth-adjustmentknob for contacting the housing to limit the travel of the lancet at thelancing position.

These and other features and advantages of representative embodiments ofthe present invention are described herein with reference to the drawingfigures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a front view of a lancing device according to one embodimentof the present invention, having its outer casing open to show internalcomponents thereof.

FIG. 2 is a rear view of the lancing device of FIG. 1.

FIG. 3 is a perspective view of a lancing device according to anotherembodiment of the invention, also having its outer casing open to showinternal components thereof.

FIG. 4 is a front view of the lancing device of FIG. 3.

FIG. 5 is another perspective view of the lancing device of FIG. 3.

FIG. 6 is a rear view of the lancing device of FIG. 3.

DETAILED DESCRIPTION

Referring now to the drawing figures, in which like reference numbersrefer to like parts throughout, preferred forms of the present inventionwill now be described by way of example embodiments. It is to beunderstood that the embodiments described and depicted herein are onlyselected examples of the many and various forms that the presentinvention may take, and that these examples are not intended to beexhaustive or limiting of the claimed invention. Also, as used in thespecification including the appended claims, the singular forms “a,”“an,” and “the” include the plural unless the context clearly dictatesotherwise. Ranges may be expressed herein as from “about” or“approximately” one particular value and/or to “about” or“approximately” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment.

With particular reference now to FIGS. 1-2, one embodiment of a lancingdevice 10 according to the present invention is shown. The device 10preferably comprises a housing 12 having a first end defining a lancetopening 14 sized and shaped to permit at least a lancet tip portion of alancet to pass therethrough. The first end of the housing optionallyfurther comprises one or more raised rings or surfaces (unshown) forapplying pressure against the subject=s skin at the lancing site toenhance flow of blood and/or other body fluid to the skin surface forcollection after lancing. The housing 12 preferably defines an internalchamber 16 for receiving a lancet upon assembly of the device 10. In thedepicted embodiment, the housing 12 is generally cylindrical, andcomprises a pair of half-shells 12 a, 12 b that are attached to oneanother upon assembly. To facilitate assembly, the half-shells 12 a, 12b may be joined to one another by one or more hinges 18, and cancomprise press fittings, clips, screws or other attachment means tosecurely engage the half-shells together upon assembly.

The housing 12 preferably further comprises at least one shoulder 20 onan internal face of a side wall bounding the chamber 16. The shoulder 20preferably defines a face extending at approximately a right angle tothe side wall of the housing 12 bounding the chamber 16. In the depictedembodiment, the shoulder 20 comprises one edge of a recess formed in theside wall, with the other edge of the recess smoothly inclined inwardlytoward the first end of the housing 12. In an alternate embodiment, theshoulder comprises one edge face of a projection outward from the sidewall, with the other edge of the projection smoothly inclined outwardlyaway from the first end of the housing 12. In the depicted embodiment,the housing 12 comprises a pair of shoulders 20 arranged on oppositesides of the chamber 16, and formed by an opposed pair of recesses 22 inthe inside face of the sidewall of the housing 12. In alternativeembodiments, three, four or more shoulders 20 are provided in spacedlocations about the periphery of the chamber 16, or a single continuousshoulder 20 is provided extending about all or a portion of theperiphery of the chamber.

The housing 12 preferably further comprises one or more flanges 30extending from the sidewall of the housing. In the depicted embodiment,the flange 30 extends inwardly from the interior face of the sidewall ofthe housing 12 proximal the second end of the housing, forming the upperboundary of the chamber 16. In alternate embodiments, the one or moreflanges extend outwardly from the exterior face of the sidewall of thehousing. In the depicted embodiment, the flange 30 is formed by twogenerally semi-circular halves, one half of the flange formed into eachhalf-shell 12 a, 12 b of the housing. In example embodiments, thehousing is formed of plastic or other moldable material, as by injectionmolding or other plastics manufacturing technique, as a one-piece,unitary molding.

The lancing device 10 preferably further comprises a lancet 40translationally mounted within the chamber 16 defined by the housing 12upon assembly. The lancet 40 preferably comprises a body portion sizedand shaped to slide freely between a cocked position and a lancingposition within the chamber 16 without significant rotation or pivoting.The lancet 40 further comprises a lancet tip having a sharp point oredge for piercing the subject's skin at the lancing site to form a woundfrom which blood or other body fluids can be collected. In the assembleddevice 10, the lancet tip extends from the body of the lancet toward thefirst end of the housing 12 and extends through the lancet opening 14(the lancing position) upon firing of the device. A sterility cap 42 ispreferably secured over the lancet tip to maintain sterility of thelancet tip until the device is to be used. The sterility cap 42preferably comprises one or more wings or other gripping surfaces tofacilitate removal by twisting and separating the cap from the lancetbody to expose the sharp lancet tip for use.

The lancet 40 preferably further comprises one or more fingers 44 forengaging the shoulder(s) 20 of the housing after firing to prevent reuseof the device. Preferably, one finger 44 is provided on the lancet 40for each shoulder 20 of the housing, so that each finger engages acooperating shoulder. Alternatively, two or more fingers 44 may engage asingle shoulder 20 of the housing. In the depicted embodiment, twofingers 44 extend outwardly from opposite sides of the body of thelancet 40, each finger extending into one of the recesses 22 formed inthe housing to engage a shoulder 20 to prevent re-cocking the deviceafter a single firing. The provision of two or more fingers 44 evenlyspaced about the periphery of the lancet 40 advantageously maintains thelancet along the central axis of the chamber 16 of the housing 12, andresists twisting and/or pivoting of the lancet within the housing as thedevice is cocked and fired. The one or more fingers 44 are preferablyformed of a resilient material such as flexible plastic, and extend in agenerally curved arc outwardly from the lancet body toward the secondend of the housing when assembled, thereby maintaining outward pressureagainst the housing throughout the traverse of the lancet. The finger(s)44 are preferably integrally formed with the lancet body, as by a singleplastic molding. Alternatively, the finger(s) 44 are separately formedand attached to the lancet 40.

The lancing device 10 preferably further comprises a spring 50 or othermeans for propelling the lancet 40 from its cocked position to itslancing position. The spring 50 is preferably engaged between the lancet40 and the housing 12. For example, in the depicted embodiment, one endof the spring 50 is secured to a retaining lug on the rear face of thebody of the lancet 40, and the other end of the spring is attachedagainst the flange 30 of the housing 12. The spring length and stiffnessare preferably selected to drive the lancet 40 from the cocked position(depicted in FIG. 1) to the lancing position wherein the lancet tipextends through the lancet opening 14 a distance sufficient to piercethe subject's skin to a desired depth at a sampling site on thesubject's fingertip or other body part against which the outside face ofthe first end of the housing 12 is pressed or placed. In furtherpreferred forms, the spring 50 also serves to retract the lancet backinto the housing after firing to prevent contact with the lancet tip. Inthe depicted embodiment, the natural (relaxed) length of the spring 50is slightly less than would be required to position the lancet 40 in thelancing position with the lancet tip extending outside of the housing12. Upon cocking and firing the device, the momentum of the lancet 40stretches the spring 50 beyond its natural length, allowing the lancetto be propelled into the lancing position with the lancet tip extendingoutside of the housing 12. The spring 50 then retracts and reachesequilibrium at about its natural length, with the attached lancet 40withdrawn into the housing 12 so that its tip is no longer exposed. Inalternate embodiments, two or more springs are provided, for example alarger drive spring for propelling the lancet 40 from its cockedposition to its lancing position, and a smaller retraction spring forwithdrawing the lancet from the lancing position back into a retractedposition fully within the housing.

The device 10 preferably further comprises a cocking arm 60 connected tothe lancet 40 for cocking the device to arm the lancet for firing. Inthe depicted embodiment, the cocking arm 60 extends from the rear end ofthe lancet 40 (i.e., the end of the lancet opposite the lancet tip). Inother embodiments, the cocking arm 60 is alternatively or additionallyconnected to one or more sides and/or the front end of the lancet 40.The cocking arm preferably includes a cocking grip 62 external of thehousing 12 to permit the user to grip and pull the cocking arm, and atleast one shaft 64 extending between the lancet 40 and the cocking grip62. In the depicted embodiment, for example, two shafts 64 are providedbetween the lancet 40 and the cocking grip 62, each shaft attached to anopposite side of the rear end of the lancet. The provision of two ormore evenly spaced shafts 64, or a single shaft located centrally,advantageously imparts force to the lancet 40 in an even manner toprevent undue twisting and/or pivoting of the lancet within the housing12 as the device is cocked.

Each of the at least one shaft(s) 64 of the cocking arm preferablyextend through a cooperating passage through the flange 30 of thehousing 12, and further comprise(s) at least one fin 66 extendingoutwardly therefrom. As used herein, the term “fin” broadly encompassesany shaft segment presenting an expanded or irregular dimension relativeto an adjacent shaft segment. The fin(s) 66 of each of the at least oneshaft(s) 64 of the cocking arm preferably releasably engage the flange30 to constrain the lancet 40 in the cocked position, once the device iscocked, until the device is triggered by the user. In the depictedembodiment, for example, one fin 66 extends outwardly from each shaft 64a distance sufficient to provide an interference fit within acooperating passage through the flange 30. The interference between thefin(s) 66 and the flange 30 is not so great as to prevent a user fromeasily cocking the device by grasping the cocking grip 62 between thethumb and forefinger and pulling away from the housing 12 to retract thefin(s) through the passages in the flange 30, but is sufficient toresist the force imparted on the lancet 40 by the spring 50 when thedevice is cocked. The device 10 then remains cocked until triggered bythe application of light finger pressure to the cocking grip 62,whereupon the fin(s) are forced back through the passages in the flange30, releasing the lancet to be propelled by the spring 50 toward thelancing position.

FIGS. 3-6 show another embodiment of the device 10, further comprising adepth-control mechanism. The depth-control mechanism preferablycomprises a depth-adjustment knob 70 mounted to the cocking arm 60 forcontacting the housing 12 to limit the travel of the lancet 40 at thelancing position. For example, in the depicted embodiment, thedepth-adjustment knob 70 extends from the cocking grip 62 inwardlytoward the housing 12, and contacts the flange 30 of the housing tolimit the travel of the lancet 40 at the lancing position. Thedepth-control mechanism preferably further comprises an adjustment dial72 having one or more indicia (visual, audible, tactile or otherwise)for allowing the user to select a desired penetration depth settingcorresponding to a respective position of the depth-adjustment knob 70.

In an example embodiment, the depth-adjustment knob 70 extends from theadjustment dial 72 and includes a threaded portion engaged within acooperating threaded passage through the cocking grip 62. In thismanner, rotation of the adjustment dial engages the threaded connectionto extend or retract the depth-adjustment knob 70. Markings on thedepth-adjustment knob 70 and the cocking grip 62 indicate the distancethe depth-adjustment knob extends beyond the cocking grip. As thedepth-adjustment knob 70 is extended further through the cocking grip 62toward the housing 12, the depth-adjustment knob contacts the flange 30of the housing earlier in the travel of the lancet, resulting in ashallower depth of penetration of the lancet tip beyond the lancetopening. Conversely, as the depth-adjustment knob 70 is retractedfurther through the cocking grip 62 away from the housing 12, thedepth-adjustment knob contacts the flange 30 of the housing later in thetravel of the lancet, resulting in a deeper penetration of the lancettip further beyond the lancet opening.

In use, the device 10 is preferably provided to the user in an uncockedstate, wherein the spring 50 is substantially relaxed, the lancet 40 ispositioned with the fingers 44 between the recesses 22 and the flange30, and the fins 66 are positioned on the internal side of the flange 30within the chamber 16 of the housing 12. The sterility cap 42 is removedprior to use by gripping its wings, twisting and lightly pulling. Thedevice is cocked by grasping the cocking grip and pulling it away fromthe housing 12 until the fins 66 are drawn through the passages in theflange 30. Interference between the fins 66 and the flange 30 constrainsthe device in the cocked position, with the spring 50 in compression.The lancet opening 14 at the first end of the housing 12 is pressedagainst the skin of the subject at the intended lancing site, preferablywith the lancet's direction of travel oriented generally perpendicularto the skin surface. The device is triggered by pressing the cockinggrip 62 toward the housing 12, pushing the fins 66 back through thepassages in the flange 30 and thereby releasing the lancet 40 to bedriven by the spring 50 toward the lancing position. At the lancingposition, the sharp lancet tip extends through the lancet opening 14 andpenetrates the subject's skin to produce a wound from which blood orother body fluids may be sampled. If desired, the user may press or pumpthe lancing device 10 against the skin after lancing to enhance the flowof body fluids at the sampling site. After lancing, the spring 50preferably retracts toward its relaxed position to draw the lancet tipback through the lancet opening 14 and into the chamber 16, where it isshielded against accidental contact. The fingers 44 of the lancet 40extend into the recesses 22 formed in the interior surface of thehousing 12 and abut against the shoulders 20 to prevent the device frombeing re-cocked and re-used, which could lead to potential bloodbornedisease transmission. The entire device may then be disposed of.

Embodiments of the device that include a depth-control mechanism areoptionally adjusted to the desired piercing depth prior to triggering.For example, in the embodiment depicted in FIGS. 3-6, the user turns thedepth-adjustment dial 72 using the indicia provided thereon as a guide,to extend or retract the depth-adjustment knob 70 to the positioncorresponding to the desired depth of penetration. When the device 10 istriggered, the depth-adjustment knob 70 contacts the flange 30 to limitthe travel of the lancet 40, thereby limiting the depth of penetrationof the lancet tip into the subject's skin at the lancing site.

While the invention has been described in its preferred forms, it willbe readily apparent to those of ordinary skill in the art that manyadditions, modifications and deletions can be made thereto withoutdeparting from the spirit and scope of the invention.

1-9. (canceled)
 10. A single-use lancing device comprising aspring-driven lancet translationally mounted within a housing, thelancet comprising at least one resilient finger extending outwardlytherefrom, each said at least one resilient finger engageable within acooperating recess formed in the housing to prevent re-use of thelancing device.
 11. The single-use lancing device of claim 10, furthercomprising a cocking arm connected to the lancet, said cocking armcomprising at least one fin for releasable engagement with a flangeprojecting inwardly from the housing to constrain the lancet in a cockedposition.
 12. The single-use lancing device of claim 11, furthercomprising a depth-adjustment knob for contacting the flange to limitthe travel of said lancet.
 13. The single-use lancing device of claim10, further comprising means for retracting the lancet into the housingafter firing.
 14. The single-use lancing device of claim 10, furthercomprising a sterility cap detachably secured to the lancet.
 15. Alancing device comprising: a housing having a first end, a second end,and at least one side wall defining a chamber between said first andsecond ends; a lancet translationally mounted within the chamber of saidhousing; a spring engaged between said lancet and said housing to drivesaid lancet from a cocked position toward a lancing position upon firingof the lancing device; a cocking arm connected to said lancet, saidcocking arm comprising at least one fin for releasable engagement withthe housing to constrain said lancet in the cocked position; and adepth-adjustment knob for contacting the housing to limit the travel ofsaid lancet at the lancing position.
 16. The lancing device of claim 15,wherein said housing comprises a flange extending transversely from saidat least one side wall, and wherein the depth-adjustment knob contactsthe flange to limit the travel of the lancet at the lancing position.17. The lancing device of claim 16, wherein said cocking arm comprisesat least one shaft having a first end connected to the lancet and asecond end connected to a cocking grip, the shaft comprising a finextending outwardly therefrom for releasable engagement with the flangeof said housing to constrain said lancet in the cocked position.
 18. Thelancing device of claim 15, wherein said lancet comprises at least oneresilient finger for engagement within a cooperating recess formed insaid housing to prevent reuse of said lancing device after firing. 19.The lancing device of claim 15, wherein the spring retracts at least atip portion of the lancet into the housing after firing.
 20. The lancingdevice of claim 15, further comprising a sterility cap detachablysecured to the lancet.
 21. A lancing device comprising: a housingdefining a shoulder therein; a lancet movable relative to the housingalong a lancing stroke, the lancet comprising a resilient memberextending therefrom, the resilient member engageable with the shoulderof the housing to prevent re-use; and a depth-adjustment member forlimiting the lancing stroke of said lancet.
 22. The lancing device ofclaim 21, wherein the shoulder comprises an end of a recess formed in aninternal wall of the housing.
 23. The lancing device of claim 21,wherein the lancet comprises a pair of resilient members extending fromopposite sides thereof, each engaging a corresponding shoulder portionin the housing.
 24. The lancing device of claim 21, wherein the housingcomprises a flange extending from a sidewall portion thereof.
 25. Thelancing device of claim 24, further comprising a spring engaged betweenthe flange of the housing and the lancet.
 26. The lancing device ofclaim 24, further comprising a cocking arm extending from the lancet andthrough the flange of the housing.
 27. The lancing device of claim 26,wherein the depth-adjustment member comprises a dial rotationallymounted to the cocking arm, and having a portion extending therefrom forcontacting the flange of the housing to limit the lancing stroke of thelancet.
 28. The lancing device of claim 26, wherein the cocking armcomprises at least one fin for releasably engaging the flange when thedevice is in a charged state.